A fuel mass within tanks of an aircraft determines in large measure a flight distance for the aircraft. Yet, measuring fuel mass, or any mass in a container, is a complicated process when a high accuracy is required. Complications arise from no sensor being able to directly measure a mass. Indeed, the mass is calculated based on a measurement of parameters that are related to the mass, such as by measuring the liquid height or volume and measuring a density value for the liquid.
In aircraft fuel gauging with contemporary aircraft applications, measuring fuel mass is further complicated by numerous other factors. The factors that complicate measuring fuel mass include complex tank geometry (which typically includes a number of interior structures), tank bending, aircraft dynamics maneuvers, fuel sloshing, acceleration effects, fuel density changes due to temperature, different fuel blends, and pressure variations with altitude and atmospheric conditions.